Convertible trailer/rail car traction unit

ABSTRACT

A conventional over-the-road tractor is modified to include a rail car coupling assembly mounting a rail car coupler in tandem behind the conventional fifth wheel for selective movement into and out of the path of conventional trailer coupling movement to permit of selective coupling with a trailer or rail car. 
     When operating in the rail car coupling mode the conventional fifth wheel boom assembly is actuated to effect, via the rail car coupling assembly, a partial weight transfer from the rail car to the traction unit.

BACKGROUND OF THE INVENTION

The more obvious advantages in the use of relatively light weighttraction vehicles to perform the functions normally assigned toswitching locomotives in railway shops, switching and rail yards arecost savings and, in the case of steerable rubber tired vehicles,maneuverability. Exemplary are the general recognitions contained inU.S. Pat. Nos. 3,198,137; 3,232,241; 3,380,397; 3,427,044 and 3,638,579.Notwithstanding the obvious savings to purchase and maintain suchvehicles as compared with conventional switching locomotives, theirspecial design parameters substantially limiting the same to the railcar environment coupled with a relatively low volume requirement yetimpose the usual high cost factor of specially designed equipment ascompared with the economics of mass production. One such special designparameter relates to achieving the required traction for rail carmovement.

The purpose of the invention is to modify a conventional, mass producedover-the-road vehicle whereby the same may be selectively employed forconventional over-the-road or rail car movement.

SUMMARY OF THE INVENTION

A conventional trailer tractor having an elevatable fifth wheel ismodified to include a rail car coupling assembly outboard of the fifthwheel. The rail car coupling assembly supports a rail car coupler forselective movement into and out of the path of trailer coupling movementundergone by the tractor during a conventional trailer couplingoperation. When the rail car coupler is supported in the path of trailercoupling movement, the tractor may be coupled to a rail car outboard ofthe fifth wheel and, when positioned out of the path of trailer couplingmovement; tractor-trailer coupling may be effected in the usual fashionwithout interference from the rail car coupler.

The rail car coupler assembly is positioned for actuating engagement bythe conventional, power operated, fifth wheel supporting boom to effecta weight transfer from the rail car to the tractor driving axle thusobviating the requirement to provide auxiliary power equipment to effectweight transfer between vehicles such as, for example, in U.S. Pat. Nos.323,283 and 3,767,069.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a broken, side elevational view of a convertible trailer/railcar traction unit in position to undergo coupling movement with a railcar;

FIG. 2 is a partial longitudinal section of the coupling end of thetraction unit illustrating the rail car coupling mode of FIG. 1;

FIG. 3 is a similar section illustrating the trailer coupling mode;

FIG. 4 is a broken rear elevation of the rail car coupling assembly inthe position of FIG. 3;

FIG. 5 is a partial top plan view of the rail car coupling assembly inthe position of FIG. 2; and

FIG. 6 is an exploded isometric view of the rail car coupling assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1, is illustrated a conventional over-the-road vehicle 10 havinga power plant 12, frame 14, front steerable wheels 16, rear drive wheels18 and the usual fifth wheel 20 supported on boom assembly 22 forvertical adjustment about pivot axis 24 under the influence of doubleacting rams 26 during trailer coupling operations.

The purpose of the present invention is to modify the aforedescribedvehicle, which may take the form of a spotter tractor of the typemanufactured by the assignee of the present invention, to incorporate arail car coupling capability and to this end the rail car couplingassembly 28, best shown in FIGS. 2, 3 and 6, is mounted on frame 14outboard of fifth wheel 20.

Rail car coupling assembly 28 includes a box frame bell crank assembly30 comprising spaced arms 32 integrated with top and bottom walls 34, 36(FIGS. 2 and 6), as by welding or the like, fulcrummed on pivot pin 38spanning frame brackets 40. A rail car coupler 42 is pivotally mountedon pin 44 at the outboard end of bell crank assembly 30 for pivotaladjusting movement between the positions of FIGS. 2 and 3 while theinboard end of the bell crank assembly mounts a heavy duty roller 46, onpin 47, in underlying relation to an integral outboard extension 48 offifth wheel boom assembly 22 as illustrated in FIGS. 2 and 3. Boomassembly 22 includes suitable cross bracing 50 which may, if desired,constitute the boom assembly construction overlying roller 46 byappropriate modification of the bell crank configuration. In eitherevent it will be apparent that retraction of rams 26, only one of whichis shown in FIG. 1, results in clockwise rotation (as viewed in FIG. 3)of boom assembly 22 about axis 24 which translates into counterclockwiserotation of bell crank assembly 30 through roller 46.

Rail car coupler 42 may be of any desired configuration to effectivelymate with a corresponding coupling element 52 of conventional designcarried by the rail car 54. To this end, the tractor mounted rail carcoupler 42 may conveniently comprise a generally vertical plate 56secured, as by welding or the like, to a generally horizontal plate 58and an offset wedge shaped web 60. Since conventional rail car couplingsare somewhat offset from the rail car centerline, the vertical couplingelement plate 56 is correspondingly offset from the tractor centerline62 as illustrated in FIG. 4. Since the trailer mounted coupler 42 doesnot normally undergo movement during a coupling operation the design ofthe same is such that the rail car coupling 52 with which it mates willoperate in conventional fashion. The web 60 acts to rigidify the plates56, 58 and may protrude through the offset opening in conventional railcar mounted coupling 52 to lend lateral stability to the coupledjunction. Horizontal plate 58 is welded or otherwise secured to spacedside plates 64 containing central apertures 66 through which pivot pin44 extends.

Positionment of the rail car coupling assembly 28 in the rail carcoupling mode of FIGS. 1 and 2 is effected by lowering boom assembly 22to the position of FIG. 2 and inserting locking pin 68 through alignedapertures 70 and 72 formed in coupling element side plates 64 and thebell crank assembly 30, respectively, as best understood from theexploded view in FIG. 6. The rail car coupler 42 is thus positionedwithin the path of coupling movement 74 (FIG. 2) which would betraversed by vehicle 10 during a coupling operation with either atrailer or rail car. When undergoing a coupling operation with a trailer(FIG. 3 position) the path of coupling movement 74 includes inclinedframe structure 76 and terminates at fifth wheel 20 while the path ofrail coupling movement terminates at rail car coupler 42 due to the factthat the same is positioned within such path of movement as shown inFIG. 2.

In order to effect a fractional weight transfer from the coupled railcar 54 to the rear driving axle of vehicle 10, rams 26, following thecoupling operation, are further retracted from the position of FIGS. 1and 2 resulting in counterclockwise movement of bell crank assembly 30from the position of FIG. 2 and consequent weight transfer from the railcar to vehicle 10 via the bell crank assembly, pivot pin 38 and fifthwheel boom assembly 22. The purpose, of course, is to apply sufficientloading to the rear wheels 18 to provide traction for moving the railcar 54. The reason for such weight transfer requirement will be readilyapparent upon consideration of the relative weights of the vehiclesinvolved. Exemplary is a single drive axle spotter trailer manufacturedby the assignee of the present invention having a total weight on thedrive axle on the order of 5,500 pounds which is insufficient to providethe necessary loading to pull a loaded rail car which may have a grossweight on the order of 200,000 pounds.

In order to convert from the rail car coupling mode of FIG. 2 to thetrailer coupling mode of FIG. 3; rams 26 are extended, locking pin 68 isremoved, coupler 42 is rotated about pivot pin 44 to the position ofFIG. 3 and pin 68 is reinserted through aligned apertures 78, 80 inspaced side plates 64 and bell crank assembly 30, respectively, as bestillustrated in FIGS. 3 and 6.

Where vehicle 10 is undergoing extensive usage in the trailer couplingmode it may be desirable to immobilize the rail car coupling assembly 28and for this purpose, a downwardly extending bracket 82 having a pinreceiving opening 84 may be provided at the aft end of frame 14. In suchevent, boom assembly 22 is appropriately lowered from the position ofFIG. 3 to permit insertion of locking pin 68 through all of alignedapertures 78, 80, 84 with such positionment moving resilient bumper 86on the bell crank assembly into compressive engagement with vehicleframe 14. Each of pivot pins 38, 44 and 47 are retained by suitable pinretainer assemblies 88.

Coupling in the trailer mode is effected in conventional fashion withcoupler 42 positioned outside the path of coupling travel 74 in eitherthe position of FIG. 3 or the position last described where pin 68extends through bracket opening 84.

Coupling in the rail car coupling mode is effected by positioning theassembly as in FIGS. 1 and 2, opening of the rail car coupling 52 andpositioning vehicle 10 astride the rail tracks. Vehicle 10 is thenbacked toward rail car 54 with coupling 42 positioned in the path ofcoupling movement 78 until the same is forceably driven into rail carcoupling 52 which, in accordance with conventional design, will closeupon coupler 42 to effect the coupling union. When the vehicle 10 is ofthe relatively light weight type described above, it will be necessaryto effect a partial weight transfer to the driving wheels by retractingrams 26 as previously described.

I claim:
 1. A convertible trailer/rail car traction unit, comprising; aself propelled vehicle supporting a fifth wheel and rail car coupler intandem for conjoint movement with said vehicle along a path of couplingmovement; and means mounting one of said fifth wheel and rail carcoupler for movement relative to said vehicle into and out of said pathof coupling movement.
 2. The traction unit of claim 1 wherein said meansincludes pivot means carried by said vehicle outboard of said fifthwheel; said rail car coupler being mounted on said pivot means; andlocking means for selectively positioning said rail car coupler clear ofand in intersecting relation to said path of coupling movement.
 3. Thetraction unit of claim 2 including a vertically movable, power operatedfifth wheel boom assembly supporting said fifth wheel; a rail carcoupler assembly mounting said pivot means and rail car coupler adjacentone end thereof; and means mounting said rail car coupler assembly onsaid vehicle for vertical movement of said rail car coupler as afunction of vertical movement of said fifth wheel boom assembly.
 4. Thetraction unit of claim 3 wherein said rail car coupling assemblyincludes a first class lever having the other end thereof in immediateunderlying juxtaposition to the outboard end of said fifth wheel boomassembly whereby powered downward movement of the outboard end of saidboom assembly elevates said rail car coupler for positioning the sameand effecting weight transfer from a coupled rail car to said tractionunit.
 5. The traction unit of claim 1 having driving wheels adjacentsaid rail car coupler; and weight transfer means, including said railcar coupler mounting means, for transferring a fraction of the weight ofa coupled rail car to said driving wheels.